Explore the vast range of titles available.

TGF-β ligands suppress growth yet can paradoxically and potently promote cancer invasion and metastasis depending on downstream pathway mutational context, such as loss of Mothers against decapentaplegic homolog 4 ( Smad4 ). Here, we characterised phenotypes and associated gene expression signatures in conditional murine intestinal adenoma with and without Smad4 . Conditional Lgr5 -CreER T2 activation in Apc fl/fl Smad4 fl/fl mice resulted in homozygote floxed alleles (Apc Δ/Δ Smad4 Δ/Δ ) and adenoma formation. The adenoma phenotype was discordant, with reduced small intestinal adenoma burden yet development of large non-metastatic caecal adenoma with nuclear localisation of phospho-Smad2/3. Derived Apc Δ/Δ Smad4 Δ/Δ adenoma organoids resisted TGF-β1 dose dependent growth arrest and cell death (IC 50 534 pM) compared to Apc Δ/Δ Smad4 +/+ (IC 50 24 pM). TGF-β1 (390 pM) altered adenoma bulk mRNA expression most significantly for Id1 low and Spp1 high in Apc Δ/Δ Smad4 Δ/Δ . Single cell RNAseq of caecal adenoma identified expansion of Lgr5 low , Pak3 high and Id1 low progenitor populations in Apc Δ/Δ Smad4 Δ/Δ . Of the 76 Smad4 and TGF-β1 dependent genes identified in Apc fl/fl Smad4 fl/fl adenoma organoids, only 7 human equivalent genes were differentially expressed in SMAD4 mutated colorectal cancer (TCGA cohorts), including ID1 low . SMAD4 low , ID1 low SPP1 high and PAK3 high all correlated with poorer survival. Murine adenoma identified Smad4 dependent gene expression signatures that require further evaluation as functional biomarker classifiers of SMAD4 mutated cancer subtypes.

ContextHeterozygous pathogenic germline variants in CDC73 predispose to the development of primary hyperparathyroidism (pHPT) and, less frequently, ossifying fibroma of the jaw and renal and uterine tumors. Clinical information on CDC73-related disorders has so far been limited to small case series.ObjectiveTo assess the clinical manifestations and penetrance in CDC73-related disorders and to improve case detection in pHPT.DesignNationwide retrospective Dutch cohort study.SettingTertiary referral center.PatientsWe studied 89 patients with pHPT referred for germline CDC73 analysis and 43 subsequently tested relatives who proved to be mutation carriers.InvestigationGermline CDC73 mutation analysis.Mean Outcome CDC73 mutation detection yield, referral rate, and CDC73-related disease penetrance.ResultsPathogenic germline CDC73 variants were identified in 11 of the 89 referred pHPT patients (12.4%), with (suspected) hyperparathyroidism–jaw tumor (HPT-JT) syndrome (n = 3), familial isolated pHPT (n = 5), apparently sporadic parathyroid carcinoma (n = 2), and apparently sporadic parathyroid adenoma (n = 1). The estimated penetrance of CDC73-related disorders was 65% at age 50 years (95% confidence interval, 48% to 82%) in 43 nonindex mutation carriers.ConclusionsGermline CDC73 analysis is recommended in individuals with (suspected) HPT-JT syndrome, familial isolated pHPT, atypical or malignant parathyroid histology, and young individuals with pHPT. These criteria would increase germline CDC73 mutation detection, enabling optimal clinical management of pHPT as well as genetic counseling and surveillance for family members at risk for developing CDC73-related disorders.Germline CDC73 mutations were frequently found in young patients with primary hyperparathyroidism and those presenting with parathyroid carcinoma and/or a positive family history.

The increase incidence of early colorectal cancer (T1 CRC) last years is mainly due to the introduction of population-based screening for CRC. T1 CRC staging based on histological criteria remains challenging and there is high variability among pathologists in the scoring of these criteria. It is crucial to unravel the biology behind the progression of adenoma into T1 CRC. Glycomic studies have reported extensively on alterations of the N-glycomic pattern in CRC; therefore, investigating these alterations may reveal new insights into the development of T1 CRC. We used matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) to spatially profile the N-glycan species in a cohort of pT1 CRC using archival formalin-fixed and paraffin-embedded (FFPE) material. To generate structural information on the observed N-glycans, CE-ESI-MS/MS was used in conjunction with MALDI-MSI. Relative intensities and glycosylation traits were calculated based on a panel of 58 N-glycans. Our analysis showed pronounced differences between normal epithelium, dysplastic, and carcinoma regions. High-mannose-type N-glycans were higher in the dysplastic region than in carcinoma, which correlates to increased proliferation of the cells. We observed changes in the cancer invasive front, including higher expression of α2,3-linked sialic acids which followed the glycosylation pattern of the carcinoma region.

Many suspected Lynch Syndrome (sLS) patients who lack mismatch repair (MMR) germline gene variants and MLH1 or MSH2 hypermethylation are currently explained by somatic MMR gene variants or, occasionally, by germline POLE variants. To further investigate unexplained sLS patients, we analyzed leukocyte and tumor DNA of 62 sLS patients using gene panel sequencing including the POLE, POLD1 and MMR genes. Forty tumors showed either one, two or more somatic MMR variants predicted to affect function. Nine sLS tumors showed a likely ultramutated phenotype and were found to carry germline (n=2) or somatic variants (n=7) in the POLE/POLD1 exonuclease domain (EDM). Six of these POLE/POLD1-EDM mutated tumors also carried somatic MMR variants. Our findings suggest that faulty proofreading may result in loss of MMR and thereby in microsatellite instability.

Background Colibactin, a genotoxin produced by polyketide synthase harboring ( pks + ) bacteria, induces double-strand breaks and chromosome aberrations. Consequently, enrichment of pks + Escherichia coli in colorectal cancer and polyposis suggests a possible carcinogenic effect in the large intestine. Additionally, specific colibactin-associated mutational signatures; SBS88 and ID18 in the Catalogue of Somatic Mutations in Cancer database, are detected in colorectal carcinomas. Previous research showed that a recurrent APC splice variant perfectly fits SBS88. Methods In this study, we explore the presence of colibactin-associated signatures and fecal pks in an unexplained polyposis cohort. Somatic targeted Next-Generation Sequencing (NGS) was performed for 379 patients. Additionally, for a subset of 29 patients, metagenomics was performed on feces and mutational signature analyses using Whole-Genome Sequencing (WGS) on Formalin-Fixed Paraffin Embedded (FFPE) colorectal tissue blocks. Results NGS showed somatic APC variants fitting SBS88 or ID18 in at least one colorectal adenoma or carcinoma in 29% of patients. Fecal metagenomic analyses revealed enriched presence of pks genes in patients with somatic variants fitting colibactin-associated signatures compared to patients without variants fitting colibactin-associated signatures. Also, mutational signature analyses showed enrichment of SBS88 and ID18 in patients with variants fitting these signatures in NGS compared to patients without. Conclusions These findings further support colibactins ability to mutagenize colorectal mucosa and contribute to the development of colorectal adenomas and carcinomas explaining a relevant part of patients with unexplained polyposis.

Abstract Context Paraganglioma (PGL) has the highest degree of heritability among human neoplasms. Current clinical understanding of germline SDHA mutation carriers is limited. Objective To estimate the contribution of SDHA mutations in PGL and to assess clinical manifestations and age-related penetrance. Design Nationwide retrospective cohort study. Setting Tertiary referral centers in the Netherlands (multicenter). Patients Germline SDHA analysis was performed in 393 patients with genetically unexplained PGL. Subsequently, 30 index SDHA mutation carriers and 56 nonindex carriers were studied. Main Outcome Measures SDHA mutation detection yield, clinical manifestations, and SDHA-related disease penetrance. Results Pathogenic germline SDHA variants were identified in 30 of the 393 referred patients with PGL (7.6%), who had head and neck PGL (21 of 174 [12%]), pheochromocytoma (4 of 191 [2%]), or sympathetic PGL (5 of 28 [18%]). The median age at diagnosis was 43 years (range, 17 to 81 years) in index SDHA mutation carriers compared with 52 years (range, 7 to 90 years) in nonmutation carriers (P = 0.002). The estimated penetrance of any SDHA-related manifestation was 10% at age 70 years (95% confidence interval, 0% to 21%) in nonindex mutation carriers. Conclusion Germline SDHA mutations are relatively common (7.6%) in patients with genetically unexplained PGL. Most index patients presented with apparently sporadic PGL. In this SDHA series, the largest assembled so far, we found the lowest penetrance of all major PGL predisposition genes. This suggests that recommendations for genetic counseling of at-risk relatives and stringency of surveillance for SDHA mutation carriers might need to be reassessed. Germline SDHA mutations were frequently found in patients with apparently sporadic (head and neck) PGL, with the lowest penetrance of all major predisposition genes.

Germline and somatic TP53 variants play a crucial role during tumorigenesis. However, genetic variations that solely affect the alternatively spliced p53 isoforms, p53β and p53γ, are not fully considered in the molecular diagnosis of Li-Fraumeni syndrome and cancer. In our search for additional cancer predisposing variants, we identify a heterozygous stop-lost variant affecting the p53β isoforms (p.*342Serext*17) in four families suspected of an autosomal dominant cancer syndrome with colorectal, breast and papillary thyroid cancers. The stop-lost variant leads to the 17 amino-acid extension of the p53β isoforms, which increases oligomerization to canonical p53α and dysregulates the expression of p53’s transcriptional targets. Our study reveals the capacity of p53β mutants to influence p53 signalling and contribute to the susceptibility of different cancer types. These findings underscore the significance of p53 isoforms and the necessity of comprehensive investigation into the entire TP53 gene in understanding cancer predisposition. Pathogenic germline variants in TP53 predispose to a variety of cancers, but variants solely affecting alternatively spliced isoforms of TP53 are understudied. Here, the authors identify a heterozygous stop-lost variant that specifically affects p53β isoforms and predisposes to familial cancer using germline whole-exome sequencing and functional genomics assays.

Endobronchial Ultrasound Guided Transbronchial Needle Aspiration (EBUS-TBNA) and Trans-esophageal Ultrasound Scanning with Fine Needle Aspiration (EUS-FNA) are important, novel techniques for the diagnosis and staging of non-small cell lung cancer (NSCLC) that have been incorporated into lung cancer staging guidelines. To guide and optimize treatment decisions, especially for NSCLC patients in stage III and IV, EGFR and KRAS mutation status is often required. The concordance rate of the mutation analysis between these cytological aspirates and histological samples obtained by surgical staging is unknown. Therefore, we studied the extent to which allele-specific quantitative real-time PCR with hydrolysis probes could be reliably performed on EBUS and EUS fine needle aspirates by comparing the results with histological material from the same patient. We analyzed a series of 43 NSCLC patients for whom cytological and histological material was available. We demonstrated that these standard molecular techniques can be accurately applied on fine needle cytological aspirates from NSCLC patients. Importantly, we show that all mutations detected in the histological material of primary tumor were also identified in the cytological samples. We conclude that molecular profiling can be reliably performed on fine needle cytology aspirates from NSCLC patients.

BackgroundPromoter hypermethylation is an important and potentially reversible mechanism of tumour suppressor gene silencing in cancer. Compounds that demethylate tumour suppressor genes and induce differentiation of cancer cells, but do not have toxic side effects, would represent an exciting option in cancer therapy. Statins are cholesterol-lowering drugs with an excellent safety profile and associated with a reduced incidence of various cancers including colorectal cancer (CRC). The authors have previously shown that statins act by activating tumour suppressive bone morphogenetic protein (BMP) signalling in CRC, increasing expression of BMP2. BMP2 is silenced by hypermethylation in gastric cancer.AimTo investigate whether BMP2 is methylated in CRC, whether statins can reverse this, and what implications this has for the use of statins in CRC.MethodsMethylation-specific PCR, bisulphite sequencing, immunoblotting, reverse transcription PCR, quantitative PCR, fluorescence-activated cell sorting analysis, an in vitro DNA methyltransferase (DNMT) assay, and cell viability studies were performed on CRC cells. The effect of statins was confirmed in a xenograft mouse model.ResultsBMP2 is silenced by promoter hypermethylation in cell lines with the hypermethylator phenotype and in primary tumours. Treatment with lovastatin downregulates DNMT activity, leading to BMP2 promoter demethylation and to upregulation of expression of BMP2 as well as other genes methylated in CRC. Statins alter gene expression, indicating a shift from a stem-like state to a more differentiated state, thereby sensitising cells to the effects of 5-fluorouracil. In a xenograft mouse model, simvastatin treatment induces BMP2 expression, leading to differentiation and reduced proliferation of CRC cells.ConclusionsStatins act as DNMT inhibitors, demethylating the BMP2 promoter, activating BMP signalling, inducing differentiation of CRC cells, and reducing ‘stemness’. This study indicates that statins may be able to be used as differentiating agents in combined or adjuvant therapy in CRC with the CpG island methylator phenotype.

A pancreatoduodenectomy specimen is complex, and there is much debate on how it is best approached by the pathologist. In this review, we provide an overview of topics relevant for current clinical practice in terms of gross dissection, and macro- and microscopic assessment of the pancreatoduodenectomy specimen with a suspicion of suspected pancreatic cancer. Tumor origin, tumor size, degree of differentiation, lymph node status, and resection margin status are universally accepted as prognostic for survival. However, different guidelines diverge on important issues, such as the diagnostic criteria for evaluating the completeness of resection. The macroscopic assessment of the site of origin in periampullary tumors and cystic lesions is influenced by the grossing method. Bi-sectioning of the head of the pancreas may offer an advantage in this respect, as this method allows for optimal visualization of the periampullary area. However, a head-to-head comparison of the assessment of clinically relevant parameters, using axial slicing versus bi-sectioning, is not available yet and the gold standard to compare both techniques prospectively might be subject of debate. Further studies are required to validate the various dissection protocols used for pancreatoduodenectomy specimens and their specific value in the assessment of pathological parameters relevant for prognosis.